Dust dissemination poses safety, health and environmental problems in many commercial environments. For instance, dust suppression is of particular concern in the coal mining industry wherein coal dust dissemination caused by wind or transit motion may lead to black lung disease if inhaled over lengthy periods of time. In other cases, the presence of coal dust may lead to possible spontaneous combustion. Similar concerns are raised when other materials such as sulfur, phosphates, clays or other finely divided ores and minerals generate dust during handling operations, mining, transportation, storage or use.
In addition to the mining industry, many other commercial activities also provide potential for dust control problems. For instance, fertilizer dust has raised health concerns due to human and animal inhalation thereof and it also may pose a problem of spontaneous combustion. The cement industry is also concerned with fugitive dust dissemination during manufacture, transport and storage operations.
Industrial sources of fugitive dust include open operations, leaks and spills, storage, disposal, transit or poor housekeeping of sundry finely divided solid particulates. The iron and steel industries are replete with examples of the above enumerated categories. Problems associated with disposal and storage of the source of fugitive dust may be exemplified by, for instance, operation of steel mill open hearth precipitators of the type having an electrostatic precipitator to control dust emissions. The dust removed by the electrostatic precipitator is typically collected in hoppers and periodically dumped into essentially closed containers known as "collecting pans". Despite the fact that connecting hoses are extended between the hopper and collecting pans, considerable fugitive dust emissions occur during material transfer. If the electrostatically removed particulate matter is to be used as landfill, severe fugitive dust emissions can occur during the dumping thereof. Natural winds have been reported as creating great dust clouds at such landfill sites. The transportation of particulates along conveyor belts and the dumping of the particulate therefrom also creates fugitive dust emission problems of the "transportation and disposal" source type.
Oil and oil based emulsions have been used for dust control purposes. For example, U.S. Pat. No. 4,417,992, Bhattacharyya et al., discloses interalia, use of oil containing emulsions comprising light paraffinic solvents, water and sundry cross-linked polymers for dust control. Kittle, U.S. Pat. No. 4,561,905 discloses the use of foamed oil/water emulsions to control coal dust dissemination. The use of aqueous based solutions of polymers for dust control is also known. Zinkan et al., U.S. Pat. No. 4,746,543 discloses the use of an aqueous solution containing a mixture of water soluble acrylic polymers with water soluble nonionic glycol polymers with anionic surfactants such as sulfonates and nonionic co-surfactants as a dust control agent. U.S. Pat. No. 4,594,268, Kirwin discloses the use of an aqueous emulsion of a methacrylate polymer as a dust control agent. Salihar, U.S. Pat. No. 4,551,261 discloses the use of a foam, comprising water a foaming agent and elastomeric water insoluble polymers for dust suppression. The use of dilatant, or highly viscous, aqueous solution of vinyl alcohol and alkali metal borate is described in U.S. Pat. No. 3,690,727, Degginger. The described combination of a borate and a polyhydroxy alcohol comprise concentrations so as to provide a viscous, dilatant solution which is used for dust suppression.